Blower



' Jan. 31, 1967 F. EJDIXON ETAL BLOWER 2 Sheets-Sheet 1 Filed Jan. 14,1965 MUN INVENTORS Farris E. Dixon Robert B. Duggon ATTORNEY Jan. 31,1967 F. E. DIXON ETAL BLOWER Filed Jan. 14, 1965 2 Sheets-Sheet 2 FIG.3.

ATTORNEY United States Patent l BLOWER Farris E. Dixon and Robert B.Duggan, both of Louisville, Ky., assignors to American Radiator &Standard Sanitary Corporation, New York, N.Y., a corporation of DelawareFiled Jan. 14, 1965, Ser. No. 425,464 3 Claims. (Cl. 230-127) Thisinvention pertains to blowers and more particularly to blowers formoving air or gases or combinations thereof to particular preselectedregions.

Blowers are used to move air and gases to preselected regions in manydevices. They are particularly useful in climate control apparatus. In aparticular climate control application, blowers are employed to direct amixture of air and gases to a combustion site where the mixture isburned to generate heat. With respect to heat generating apparatus,there has become available a high heat flux type boiler with a low watercontent, a large combustion area, and low mass relative to the rate atwhich fuel is burned. Insuch a boiler the heat exchanger surrounds aparticular type burner. The burner includes a cylinder of heat resistantfabrics which because of their large number of combustion sites produceheat with greater efficiency, at higher temperatures and at fasterrates. However, such burners require a premixed combination of air and agaseous hydrocarbon which is fed to the burner under sufliciently highpressureto pass through the fabric. This pressure is relatively high forblowers in which the gases are centrifugally collected in a scroll.Along with the requirement that the delivery of the gaseous mixture beat a relatively high pressure there is the requirement that the deliverybe at a relatively low rate. While the two requirements can be satisfiedby the use of a high capacity blower whose output is restricted down toprovide the :high pressure and low delivery capacity, such a blower isexpensive and inefficiently used. Furthermore, such a blower is quitenoisy.

It is, therefore, a general object of the invention to provide animproved blower.

It is another object of the invention to provide a blower which has alow delivery rate and a high delivery pres sure, and at the same time ismuch less expensive than presently available blowers.

It is a further object of the invention to provide an improved blowerwheel for a blower which when operating is relatively quiet.

It is yet a further object of the invention to provide an improvedscroll for a blower which is simple to fabricate.

Briefly, the invention contemplates a blower which includes a scroll anda blower wheel within the scroll. The scroll comprises oppositelyextending arcuate inner and outer peripheral walls. The separationbetween the walls and the axial lengths of the walls increases along thearcuate direction. First and second end walls abut the peripheral wallswith the spacing between the end walls increasing along the :arcuatedirection. The blower wheel includes an axle portion and a plurality ofblades extending radially from the axle portion. Successive blades ofthe plurality of blades have different radial lengths.

Other objects, the features and advantages of the invention will beapparent from the following detailed descrip tion when read with theaccompanying drawings which show, by way of example and not limitation,the now preferred embodiment of the invention.

In the drawings:

FIG. 1 is an end view of a blower showing the relation between thescroll and blower wheel of the blower in accordance with the invention;

3,391,472 Patented Jan. 31, 1967 FIG. 2 is a side view of the scroll ofFIG. 1;

FIG. 3 is a plan view of one embodiment of the blower wheel of FIG. 1;and

FIG. 4 is a side view of the blower wheel of FIG. 1 showing itsconnection via an axle to a motor.

Referring to FIG. 1, the blower 19 is shown including a scroll 12 andthe blower wheel 14 impeller with scroll 12. Scroll 12 is of thecentrifugal type including two parts 12A and 123 (FIG. 2). Part 12A,which is of a vacuum molded plastic, includes inner and outer peripheralwalls 16 and 18 and an end wall 20. End wall 20 is integral withperipheral walls 16 and 18. As is apparent from FIG. 1, the peripheralwalls 16 and 18 are arcuate and preferably have spiral projections.Furthermore, the radial separation between the oppositely disposedperipheral walls 16 and 18 smoothly and continuously increases along thearcuate direction in the direction of rotation of the blower wheel 14.In addition, as is clearly shown in FIG. 2, the axial width W of theperipheral walls 16 and 18 smoothly and continuously increases along thearcuate direction toward the outlet 21.

Part 1213 is the second end wall of the scroll and is a flat plate ofsheet metal which can incorporate a motor mount and/or structuralsupport. Part 12B is joined to part 12A along the flange portion 22thereof. Part 1213 is further provided with a central aperture which isboth the inlet and provides a passageway for the axle 24 which isconnected to blower wheel 14.

Blower wheel 14, which is of galvanized steel or aluminum, will now bedescribed, primarily, with respect to FIGS. 3 and 4.

Blower wheel 14 is an integral structure including an axle or hubportion 26 and a plurality of circumferentially equidistantly spacedvane portions 28 radially extending from axle portion 26. The vaneportions 28 generally lie in a plane which is perpendicular to the axisof rotation R. Corrugations 30 are formed in vanes 28-to providemechanical rigidity thereto. Each of the vanes includes a pair of blades32, 34. The blades 32 and 34 laterally extend from the vane plane andpreferably make a right angle therewith. Furthermore, not only are theblades 32 and 34 perpendicular to the vane plane but lie in divergingplanes which are tangent to a circle having its center on the axis ofrotation R. As the diameter of the circle approaches zero the divergingplanes approach radial planes which include the axis of rotation R. Inother words, the blades extend in a mutual diverging relationship fromthe axle portions 26.

In each blade pair, the radial displacement of the outer blade tips 36and 38 is the same radial distance from the axis of rotation R. However,the inner blade tips 40 and 42 are different radial distances from theaxis of rotation R. Therefore, in each blade pair, the length of blade32, i.e., the distance from the inner blade tip to the outer blade tipis greater than the length of blade 34. In fact, the radial of blade 32is preferably 1.5 times longer. Furthermore, the angular separationbetween t-he blade 32 and the blade 34 of one blade pair is less thanthe angular separation between the blade 32 and the blade 34A of theadjacent blade pair 34A, 32A. In fact, the angular separation betweenblades 34A and 32 is preferably 25 degrees, and the angular separationbetween blades 34 and 32 is preferably 20 degrees. Hence, it should beapparent that successive blades are of different length and havedifferent angular separations from their immediate adjacent blades. Inaddition, the width W of the blades is preferably less than 0.5 timesthe length of the blade.

Axle 24 is fixed to blower wheel 18 by passing through a central holethereof and being peened over a washer 44. A central hole in axle 24accepts the shaft 46 of motor 48. Set screws 50 fix axle 24 to shaft 46.

There has thus been shown an improved blower which quietly moves gasesat high pressure and low capacity. In a working embodiment, a bloweraccording to the invention pumps an air-gas mixture at a delivery rateof twenty-five cubic feet per minute with a pressure of 2.8 inches ofwater. The blower wheel which was driven at 3000 revolutions per minutehad a radius of four inches with the longer blades thereof havinglengths of about 2.25 inches and widths of about 0. 63 inch.

While only one embodiment of the invention has been shown and describedin detail there will now be obvious to those skilled in the art manymodifications and variations which satisfy many or all of the objects ofthe invention. However, these modifications and variations will notdepart from the spirit of the invention as defined by the appendedclaims.

What is claimed is:

1. A blower impeller comprising a central substantially flat disc-likehub portion, an axle member secured to said hub portion centrallythereof and defining the axis of rotation of the impeller, and aplurality of circumferentially equidistantly spaced impeller blades onthe hub portion projecting equal distances radially therefrom, eachimpeller blade being substantially U-sh'aped in cross section and havinga frontal substantially flat face lying in a common plane with thefrontal faces of the other blades, said plane perpendicular to the axisof rotation of the impeller, each impeller blade also having opposedsubstantially flat sides which project rearwardly of the frontal facesubstantially at right angles thereto, the rear edges of said sides ofall blades terminating in a common plane parallel to the first-namedcommon plane so that all of said blades are of the same depth axially ofthe impeller, all of said blades beingof the same circumferential width,said circumferential width being somewhat less than the equalcircumferential spacing of the blades, one side of each impeller bladebeing radially shorter than the opposite side thereof and having itsinner end terminating a greater distance radially from the center of theimpeller than said opposite side, the radially shorter sides of theblades being adjacent to the radially longer sides of the next blade ofthe impeller, whereby short and long impeller blade sides arealternately arranged around the circumference of the impeller with alesser circumferential space between short and long sides of each bladethan between short and long sides of adjacent blades.

2. A high pressure low delivery rate blower comprising a blower impelleras defined by claim 1, and a scroll receiving and enclosing saidimpeller and having an axial inlet and a substantially tangentialoutlet, said scroll having a substantially circumferential passagesubstantially surrounding the circumference of the impeller andgradually increasing in width radially from a point on saidcircumference toward the scroll outlet, the scroll having a flat sidenormal to the axis of rotation of the impeller and facing the rearwardedges of the impeller blade sides and having an oblique side facing saidfrontal faces of the impeller blades.

3. An impeller fora blower comprising a unitary sheet metal impellerbody, said body comprising a central disclike :hub portion adapted forattachment to a driving shaft, and a plurality of circumferentiallyequidistantly spaced blades on the hub portion projecting equaldistances radially therefrom, each blade being substantially U-shaped incross section and including a frontal fiat face and opposed flat sidesarranged perpendicular to said flat face, the frontal faces of allblades lying in a common plane normal to the axis of rotation oftheimpel-ler and all of said blade sides radiating from the center ofthe impeller, one side of each blade being radially shorter than theopposite side thereof and having its inner end positioned "a greaterdistance radially from the center of the impeller than the correspondingend of said opposite side, the rear edges of all of said blade sidesterminating in a common plane parallel to the first-named common plane,the axial depth of said blades being equal and the axial depth beingmaterially less than the circumferential width and the radial length ofsaid blades, the circumferential width of each blade between its sidesbeing less than the circumferential spacing of the blades, the radially.shorter side of each blade lying next to the longer side of theadjacent blade.

References Cited by the Examiner UNITED STATES PATENTS 42,716 5/1864Rammell 103-115 867,874 10/1907 Capell 230-134 1,083,739 1/1914 Guyer103-115 1,404,298 1/1922 Jacobs 230-134 1,817,169 8/1931 Schwitzer etal. 230-134 1,868,008 7/1932 Gardner 230- 1,895,488 1/1933 Reisinger230-127 2,176,325 10/1939 Bretzloff et al. 230-134 2,715,814 8/1955 Barr230-127 2,976,352 3/1961 Attlla 230-117 3,006,603 10/1961 Caruso et al230-127 3,145,912 8/1964 Weis 230-127 FOREIGN PATENTS 72,020 5/1943Czechoslovakia. 462,206 11/1913 France. 165,330 11/1905 Germany.

11,366 1909 Great Britain. 414,593 8/1934 Great Britain. 519,630 4/1940Great Britain. 941,343 11/1963 Great Britain.

DONLEY .l. STOCKING, Primary Examiner. HENRY F. RADUAZO, Examiner.

1. A BLOWER IMPELLER COMPRISING A CENTRAL SUBSTANTIALLY FLAT DISC-LIKEHUB PORTION, AN AXLE MEMBER SECURED TO SAID HUB PORTION CENTRALLYTHEREOF AND DEFINING THE AXIS OF ROTATION OF THE IMPELLER, AND APLURALITY OF CIRCUMFERENTIALLY EQUIDISTANTLY SPACED IMPELLER BLADES ONTHE HUB PORTION PROJECTING EQUAL DISTANCES RADIALLY THEREFROM, EACHIMPELLER BLADE BEING SUBSTANTIALLY U-SHAPED IN CROSS SECTION AND HAVINGA FRONTAL SUBSTANTIALLY FLAT FACE LYING IN A COMMON PLANE WITH THEFRONTAL FACES OF THE OTHER BLADES, SAID PLANE PERPENDICULAR TO THE AXISOF ROTATION OF THE IMPELLER, EACH IMPELLER BLADE ALSO HAVING OPPOSEDSUBSTANTIALLY FLAT SIDES WHICH PROJECT REARWARDLY OF THE FRONTAL FACESUBSTANTIALLY AT RIGHT ANGLES THERETO, THE REAR EDGES OF SAID SIDES OFALL BLADES TERMINATING IN A COMMON PLANE PARALLEL TO THE FIRST-NAMEDCOMMON PLANE SO THAT ALL OF SAID BLADES ARE OF THE SAME DEPTH AXIALLY OFTHE IMPELLER, ALL OF SAID BLADES BEING OF THE SAME CIRCUMFERENTIALWIDTH, SAID CIRCUMFERENTIAL WIDTH BEING SOMEWHAT LESS THAN THE EQUALCIRCUMFERENTIAL SPACING OF THE BLADES, ONE SIDE OF EACH IMPELLER BLADEBEING RADIALLY SHORTER THAN THE OPPOSITE SIDE THEREOF AND HAVING ITSINNER END TERMINATING A GREATER DISTANCE RADIALLY FROM THE CENTER OF THEIMPELLER THAN SAID OPPOSITE SIDE, THE RADIALLY SHORTER SIDES OF THEBLADES BEING ADJACENT TO THE RADIALLY LONGER SIDES OF THE NEXT BLADE OFTHE IMPELLER, WHEREBY SHORT AND LONG IMPELLER BLADE SIDES AREALTERNATELY ARRANGED AROUND THE CIRCUMFERENCE OF THE IMPELLER WITH ALESSER CIRCUMFERENTIALLY SPACE BETWEEN SHORT AND LONG SIDES OF EACHBLADE THAN BETWEEN SHORT AND LONG SIDES OF ADJACENT BLADES.